Gas scrubber

Abstract

Gases that are to be scrubbed, particularly flue gases, pass through an inlet line (14) into a processing area (9) wherein the gases are exposed to the effects of a scrubbing agent that is contained in a bath (4). To this end, the liquid is sprayed by means of a rotating disc arrangement (17), the discs of which are coated--preferably through a hollow shaft (18)--with a layer of the scrubbing agent, this coating then being separated from the rotating discs as a result of centrifugal forces, with the attendant formation of an annular spray zone. The gas scrubber can trap sulfur dioxide that is contained in the flue gases. To this end, water is used as the scrubbing agent, and sodium carbonate (soda) is added to this. The sodium carbonate is converted with the water and with the carbon dioxide that is contained in the flue gas to hydrosodic carbonate, and this, together with the sulfur dioxide that is contained in the flue gas forms sodium sulfate if oxygen or additional air is introduced through the opening (26) into the processing area (9), and this sodium sulfate then collects on the bottom of the bath (4) in the form of a sediment.

We claim: 
     
       1. A gas scrubber, comprising a processing chamber having a gas feeding area; and at least one spraying device positioned in said chamber and including a rotary hollow shaft having a vertical central axis, and a disc arrangement having discs mounted on said shaft to rotate therewith about said axis, said shaft having openings formed adjacent to each disc, said discs being coated with a cleaning liquid passing through said shaft and said openings and adhering to the discs and sprayed from said discs under the action of centrifugal forces outwardly in the form of an annular spray zone, each disc having perforations and being formed at a periphery thereof with recesses forming aerodynamically operating elements, said recesses being formed by cutouts at said periphery, said elements being formed as blades twisted at an adjusted angle relative to a plane of the disc so that gas being cleaned upon the rotation of said discs is forced radially outwardly and also axially of said disc arrangement away from said gas feeding area. 
     
     
       2. The scrubber as defined in claim 1, further including a cylindrical housing accommodating said disc arrangement and surrounding the same at a radial distance therefrom, a radial distance between the periphery of each disc and said housing being greater the remoter is a respective disc from said gas feeding area. 
     
     
       3. The scrubber as defined in claim 1, and further including a drying chamber, said disc arrangement being driven by a motor; and including a blower for cooling said motor, an exhaust gas of said blower being partially fed into said processing chamber and partially into said drying chamber, said drying chamber being connected with said processing chamber for drying a cleaned gas. 
     
     
       4. The scrubber as defined in claim 1, wherein said chamber has a bath filled with the cleaning liquid and positioned below said disc arrangement, the gas to be cleaned being forced downwardly towards said bath. 
     
     
       5. The scrubber as defined in claim 4, for cleaning exhaust gases, wherein an additional air is fed into the scrubber and a neutralizing agent is added in said bath. 
     
     
       6. The scrubber as defined in claim 5, wherein said neutralizing agent is sodium carbonate. 
     
     
       7. The scrubber as defined in claim 4, said bath being formed as a sedimentation basin; and further including a drying container into which sludge, collected at a bottom of said basin, is fed, and a gas line leading to the scrubber and in which said drying container is inserted. 
     
     
       8. The scrubber as defined in claim 7, wherein said drying container is a closed arrangement and is provided with a vacuum pump for producing vacuum in said drying container, and a suction line interconnected between said bath and said drying container so that a sludge collected in said bath can be moved through said suction line from a bottom of said sedimentation basin into said drying container. 
     
     
       9. The scrubber as defined in claim 4, wherein said shaft has an upper end at which the shaft is supported, and a lower end which is immersed in said bath, said shaft being provided at said lower end with propeller blades positioned inside said shaft and forcing the cleaning liquid from said bath through said shaft, and said openings towards said discs. 
     
     
       10. The scrubber as defined in claim 9, wherein said shaft is motor driven and is connected at said upper end immediately to a shaft of a motor for the rotation of said disc arrangement, the shaft of the motor having a bearing for radially and axially guiding said shaft. 
     
     
       11. The scrubber as defined in claim 9, further including a horizontal baffle positioned in said bath, said lower end with said propeller blades being positioned above said baffle, and struts radially projecting from said axis and positioned in said bath, said struts counteracting an annular flow of the liquid of said bath above said baffle when said shaft is rotated. 
     
     
       12. The scrubber as defined in claim 4, further including a heat exchanger which receives the gas to be cleaned, said heat exchanger being arranged so that a condensate formed therein drips into said bath. 
     
     
       13. The scrubber as defined in claim 12, further including a ring-shapd chamber surrounding said processing chamber and housing said heat exchanger, said processing chamber being limited from below by an upper surface of said bath. 
     
     
       14. The scrubber as defined in claim 12, wherein said heat exchanger is arranged so that it receives the gas to be cleaned before it enters said gas feeding area.